Stem mapping of all trees greater than 15 cm dbh has
been completed on the 10.24 hectare watershed (No. 10) at H. J.
Andrews intensive study site. Using a 25 m grid system, mapping
of vegetation into 7 plant communities and then into 4 habitat
types has also been completed....
Early in the planning of the Coniferous Biome program It was recognized that experimental watersheds 2 and 3 in the H. J. Andrews Experimental Forest might provide ideal study sites for certain phases of the Biome
program. A study was funded during year 1 (1970) to provide necessary background ecological...
Early in the planning of the Coniferous Biome research program, it was recognized that Experimental Watersheds 6, 7, and 8 in the
H. J. Andrews Experimental Forest might provide ideal study sites for certain phases of the Biome program. A study was funded during year 1 (1970) to provide necessary...
Variation in nutrient content of forest trees is discussed using the
data from literature plus data collected by the authors. Sections are
included on sampling and methods of expression of nutrient content. The
emphasis is on possible causes of variation, which involves nutrient
variation between years, within the year, and...
Measurement of plant moisture stress of 1-2 m understory conifers
was made in "reference stands" on the H. J. Andrews Experimental
Forest in 1970-1972. Maximum stress each year (measured between midnight
and dawn) is closely correlated with the position of each community
along one axis of an ordination of the...
Air temperatures at i m and soil temperatures at 2C cm are reported for
twenty-one forest stands in the central Western Cascader of Oregon. Records
began in 1970 for some stands, in 1971 or 1972 for most. Temperature Growth
Index for a stand, based on temperature effects on Douglas-fir seedling...
The objective of this study is to develop a mathematical model to relate the production of juvenile sockeye salmon in the Wood River
Lake system to parent stock size, primary and secondary production, population size of predators and competitors, and abiotic variables.
"We have developed graphical and logical models for explaining the production of a consumer on the basis of the capacity of an ecosystem to produce that consumer (the productivity of the system for that consumer), on the basis of the biomass of the consumer, and on the basis of the...
The physical framework or matrix in which the biological processes of aquatic ecosystems occur is currently under investigation at the Castle Lake Research Station. Special attention has been given these physical parameters in view of their close interrelationship with important biological properties within the lake (as exemplified by the rate...
In an initial research proposal of December 1969, the scientists of the Coniferous Forest Biome (CFB), an ecosystem study centered in the Pacific Northwest and part of the larger International Biological Programme (IBP), expressed optimism that computer simulations and systems modeling could transform empirical knowledge of the carbon, water, and...
The food habits of yellow perch in Lake Washington were studied over a period
of nine months. Altogether, 549 yellow perch were examined for the stomach
contents. The food consisted mainly of cottids, mysid shrimp, and chironomid
pupae and larvae; the predominant food item being the mysid shrimp.
There was...
Further development of an environmental grid for interpreting plant distribution and growth took place this last year as an attempt to solve problems associated with spatial diversity in ecosystems. Special emphasis was placed on developing more universal integrated indexes to environment,
ones that might permit wide extrapolation throughout the range...
The attack spatial pattern of the Douglas-fir beetle, Dendroctonus
pseudotsugae Hopkins was shown to be regular within a given subarea
of bark on its host, Pseudotsugae menziesii (Mirb.) Franco. Empirical
arguments were advanced which indicated the uniform spacing of attacks
was the result of a beetle controlled spacing mechanism dependent...
Felled second-growth Douglas-fir trees in western Washington were used
to determine the attack distribution and develop a sampling technique
for an endemic Douglas-fir beetle, Dendroctonue peeudotaugae Hopk.
(Coleoptera: Scolytidae) population. The attack density varied by
circumferential position. The lowest density was on the upper bole
and the highest on one...